Then for each new command you call add on this object so that for a call to line of the form

line $x, $y, $opt;

the call to add would be like

$state->add(\&line, 'line', [$x, $y], $opt);

which is stored internally as:

[\&line, 'line', [$x, $y], $opt]

The state can later be extracted using get which returns the state object which is an array of anonymous arrays like the one above where the first object is a reference to the function, the second an anomymous array of arguments to the function and finally an anonymous hash with options to the command.

If you know the order in which you inserted commands they can be removed by calling remove with the number in the stack. No further interaction is implemented except clear which clears the stack and copy which returns a "deep" copy of the state.

Jarle Brinchmann (jarle@astro.ox.ac.uk) after some prodding by Karl Glazebrook.

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